I fish in the nastiest Hydrilla, Milfoil, and canopies of all kinds in the Florida Swamps and I know what you mean when you say "Nothing is Weedless" and essentially that is true since all the algae, moss, and junk alway's end up on your Jig, Punch Rig, Texas rig etc. etc...
However, It is important to realize that If you are flipping a 1 ounce or heavier punch rig or jig into a patch of Hydrilla and it picks up some moss on the way down, I have never noticed the fish shying away. When I flip into a spot my goal is to get it in clean and quiet, and most strikes happen as soon as the Jig breaks through cover or hits bottom. If you give the jig a good lift instead of letting it shake on the bottom first, that should get the junk off the knot area and in the crevice, but like AJ is saying.....I find the Punch Rig to be the most weedless of all, and as long as I rig my bait properly (leaving room for the hook shank to slide during the set and not having the weight get in the way) I would say my hookup percentage is about the same overall because I get more strikes with a punch rig and it also doubles as a swim jig and for some reason it actually works better than a true swim jig for whatever reason, but here are a few tips that were shown to me by guys who live by the heavy broom stick and nothing but jigs and Pork.....
1- Scent and Oil added to your bait will help it slide in and out of cover much better, plus it will give you some extra time on a hook set and I like to use Megastrike and I often mix it up with some vegetable oil or straight worm oil, but I am dipping a lot....I also find that adding some glitter can help if they are feeding on shad or other forage...
2- For Jigs, the key is picking the right weight. I always used to go 3/8-1/2 and 3/4 was the heaviest I would think of before tungsten, and in the last few years I have finally become comfortable flipping with 1 ounce and up, and in Healthy Hydrilla, the water is usually clear, so a faster falling bait is key, and if moss is an issue, use a slim soft bait like the Zoom Speed worm with paddle tail, Bass Pro Swizzle stick, Culprit Fat Max is a favorite of mine as it is designed for cover, and the Regular Stick worm is not a bad idea either as straight worms with straight offset hooks and a hitchhiker helps (Siebert Jigs has everything you need and his pricing is better than Bass Pro and email the owner and tell him what you are looking to do and he will get you some killer custom jigs and punch rigs that last much longer than standard jigs.
3- Don't worry so much about weeds stuck on the top of your jig, the action is coming from the skirt and trailer, I love to bulk up Jigs by using a spider Grub as a trailer, but in situations when I am in the trash, I use a florida screw in weight or pegged sinker, punch skirt optional, make sure you do not have any areas for muck to lock in on, someone mentioned knots earlier and that is important but also how the bait enters the water is most important...Here is a great bait for flipping Hydrilla and then working back to the boat and you can get away with lighter weights as the bait is super weedless and does it all...
YUM HOUDINI SHAD FLUKE/BUZZ WORM/Senko-4 tail options, just re introduced the bait as New and for $2.99 it is a steal of an all purpose soft bait...The Strike King Caffiene shad is fantastic but the Houdini Shad is a good alternative to the Paddle tails and is more streamlined.Also look at Culprit Incredicraw slim, and D.O.A. CAL paddle tail in gold rush is a fantastic flipping bait that you can also swim which I like in Hyrdilla, fish spook easier and often you need to get back and make long casts and truly work holes, if it is too thick than it is not good and will not hold fish if it is top to bottom choked...Sorry for the ramble, but try the scent, oil, thin worms, and the punch skirt helps and adds extra flare, or flip a spider grub, Houdini shad, fat max, senko, or Fluke...